Electrical measuring system



Aug. 28, 1945. A; CARSON El'AL 7 2,383,770

ELECTRICAL MEASURING SYSTEM Filed Nov. 7, 1942 LS 1v- Selector Indicator Lain v.5

.31 us/Z/ Imizcator Lamps QKQ) $1 3 1 WWW Impulse Counter INVENTORS ugCarsol/a fl/ZPqz ne ATTORNEY Patented Aug. 28, 1945 UNITED STATES PATENT OFFICE ELECTRFCAL MEASURING SYSTEM Arthur Carson and Irving Payne, Richmond, Va., assignors to American Telephone and Telegraph Company, a corporation ofNew York Application November 7, 1942, Serial No. 464,914

Claims. (o1. 1-79 1'15. 2)

This invention relates to electrical counting and testing systems and is particularly suitable for telephone and like systems which employ a large number of lines or circuits many of which may be in use at the same time.

' In telephone and electrical systems generally and more particularly in systems of the telephone exchange type where a large number of lines or circuits are employed for purposes of communication, many of which are in use at the same time, it is necessary to ascertain at intervals how many of the various lines or circuits are in use at any one time. It has previously been the practice to send a number of attendants through the plant to observe how many of the switches associated with the various lines or circuits are in their operative positions. This practice furnishes information that is quite inaccurate, requires considerable personnel and is otherwise unsatisfactory. I

In order to improve this situation an integrating system of a type disclosed in this application has been proposed by which it is possible to determine within a very brief interval of time how many of the various lines or circuits in a telephone or other system are operated or busy at substantially the same time. The

many hundreds of lines or circuits.

In its more general aspects the invention comprises a master selector, a plurality of other selectors all of which are of the rotary type and a counter for indicating how many of the various lines or circuits have a predetermined electrical condition, as for example, a grounded condition. As is well known, such a condition develops when a telephone line becomes busy. Each of the selectors controlled by the master selectorincludes a brush and a plurality of contacts to'which are connected a plurality of the lines or circuits to be tested or examined. The master selector is operated step-by-step and connects the counter to the brushes of the other selectors. The apparatus is arranged so that with each step-bystep operation of the master selector the other selectors are operated one by one in regular order. Thus the Various lines or circuits connected to the various selectors will be connected one 'by one through the master selector to the counter, and the counter will register each time it is connected to a line or circuit exhibiting a predetermined electrical condition of, for example, ground. 1

This invention will be better understood from the more detailed description hereinafter following when read in connection with the accompanying drawing showing one embodiment of the invention merely for the purpose of i1- lustration.

Referring to the drawing the master or control selector is designated CS and it comprises three brushes BJl, BJz and BJ3, all mounted on a common shaft. This master or control selector CS will be employed to control the operation of a plurality of additional selectors such as SL1, SL5 and SLn, SL1 being the first of the selectors controlledby the master selector. CS, the selector SLn the last of the selectors so controlled and SL5 one of the intermediate selectors. The selectors SL1, SL5 and SLR each comprise six brushes BKQ to BKs, BLO to BL5, and BMO to BM5, respectively, all of the six brushes of each selector being mounted on a common shaft so as to rotate in unison. Each of these brushes moves over a segment or are in awellknown manner.

The brush BKO and its associated segment at the extreme right of the selector SL1, for example, are employed to start the selector SL1 in operation, while the other brushes BK1 to 3K5 may be rotated so as to contact each of a plurality of lines or circuits, thelines K1 to Km ,being contacted by brush BK1, lines K21 to K2n being contacted by b-r'ushBKz, lines K31 to Kim being contacted by brush BKs, lines K41 to K411 being contacted by brush BK4 and lines K51 to Kfin being contacted bybrushBKs. The brushes 0f the other selectors are likewise connected to similar groups of lines or circuits.

45 five terminals may be contacted by brush BJz' The master or control selector CS and the adat a subsequent time, whereupon brush BJz will be connected through a conductor 15. to the stepping'magnet SP5 which is wired to the brush BLO for starting the selector SL5. Likewise a subsequent group of terminals are wired through a conductor 20 to the stepping magnet SP1, and brush BMO of the last selector SLR. The brush BJz may, therefore, be considered as the one which controls the starting and stepping action 5 of the various selectors SL1 to SLn.

The brush BJs of the master or control selector CS has its first five terminals, 2|, 22, 23, 24 and 25 connected respectively to the brushes BK1, BKz, 3K3, BKd and BKs of the first selector SL1. Similarly two other groups of five terminals are wired to corresponding brushes of the other selectors SL5 and SLn as shown. The brush BJ; is alsoconnected to an impulse counter IC so that as the brush BK1, for example, of selector SL1-contacts the various circuits K1 to K111, a grounded condition on each of these circuits will cause the impulse counter to register the grounded condition, as will be explained hereinafter. The impulse counter 10 will, therefore, indicate how many of, these circuits are grounded, i. e., are busy. Thus the brush BJa may be considered as the one employed for selecting the various brushes of the difi'erent'selectors SL to SLn one at a time to register at the impulse counter 10 the number of busy circuits contacted by the various brushes of the selectors.

The brush BJ1 of the master or control selector CS will contact a plurality of terminals which are arranged in groups of five as are the other two brushes BJ; and 3.13 The first terminals of each of these various groups are wired together by a conductor 26 and are connected in common to the lamp LE1, Likewise the conductors 21 to 38 connect the other terminals of these groups to the lamps LBz to LBs, as shown in the drawing. The brush BJ1 may, therefore, be considered as that one which controls the illumination of one of the lamps LB1 to LBs, thereby indicating to the operator which one of the various brushes such as BK1 of a particular selector such as SL1 is being utilized in the counting process at a particular time. Another group oflamps LS1to LSn is connected respectively to the various stepping magnets such as SP1 to SPn and these are illuminated when the respective stepping magnets are operated These lamps indicate which of the various selectors SL1 to SLn are in operation.

The method of operation of the apparatus shown in the drawing is as follows: The operator will operate the key K0 momentarily. This will close an obvious circuit through a starting magnet ST which will become energized. 1 The operation of the startingmagnet ST will cause the stepping magnet SP0 of the master or control selector CS to become operated, theoperating circuit including battery B1, the winding of stepping magnet SPO, the inner armature and make contact of starting magnet ST and ground. Upon the operation of the stepping magnet SP0 the brushes BJ 1, BJz and BJa of the control selector CS will be'stepped in unison'in a counter-clockwise direction through one step in a well known manner. When the brush BJz contacts its first terminal, it will cause the operation of the stepping magnet SP1 which controls the selector SL1, the interconnected circuit including battery B1, brush BJa, conductor I I, the winding of the step- I ping magnet SP1 and its armature and back contact, the brush BKQ, conductor 3|, the outer armature and make contact of starting magnet ST and ground. The stepping magnet SP1; therefore, will step all of the brushes BK1, to BKs of selector SL1 in a counter-clockwise direction through one step. A1; the same time the lamp LE1 willbecome illuminated, the circuit for lamp LE1 including battery B2, resistor 32, lamp LB1, brush BJ1 and ground. Lamp LB1 will, therefore, indicate that the apparatus is proceeding to count the number of grounded or busy circuits connected to the terminals of the first testing are of one of the switches, as for example, the circuits numbered K1 to K111. Moreover, the lamp LS1 will also become illuminated, the interconnecting circuit including battery B1, brllsh BJz of selector CS, conductor I I, lamp LS1, resistor 33 and ground. The lamp LS1 will, therefore, indicate that the first selector SL1 is in operation.

Immediately after the steppingmagnet SP1 of selector SL1 operates, it breaks its own circuit established through its armature and back contact. However, this stepping magnet will be reenergized over a circuit which is completed through the other terminals of the first are or segment of selector SL1 which are connected together and grounded. Thus th circuit then established over stepping magnet SP1 will include battery B1, brush BJ2, conductor II, the winding of magnet SP1 and its armature and back contact, brush EKG and the first contact of brush BKO, together with the other contacts connected thereto and ground. Thus the stepping magnet SP1 will be re-operated, thereby allowing the various brushes BQo to BKs to rotate through the rest of their arcs or segments,

As the brush BK1 of selector SL1 traverses the rest of its are or segment, for example, it will contact the various lines or circuits K1 to K111 in regular progression. If, for example, the first of these circuits K1 is grounded, the impulse counter 10 will become operated, the operating circuit including battery B3, resistor 34, impulse counter IC, brush BJa of selector CS, contact 2|, brush BK1 and line K1, which is now grounded. Each of the other lines K2 to K111 will be progressively contacted by brush BK1, each such contact being of but a momentary duration, yet long enough to allow the impulse counter 10 to register a grounded condition if such exists. The impulse counter IC will, therefore, register in an integrated form the number of lines of circuits which are busy.

. When the brushes BKO to BKs of selector SL1 reach their last contact-which corresponds to the contact closed by those brushes when the selector SL1 is back in its starting position, as shown in the drawingthe starting magnet ST will become re-operated The new circuit for starting magnet ST includes the winding of starting magnet ST, the conductor 4|, the brush BK1 of selector SL1, contact 2| and brush BJs of selector CS, impulse counter 1C resistor .34, battery B3 and ground. Although the starting magnet ST is re-operated by the completion of this circuit, the impulse counter IC will remain unoperated because'of the large resistance present in the winding of relay ST. As the starting magnet ST becomes re-operated, it will again cause the re-operation of the stepping magnets SP0 and 1 SP1. The circuit for the magnet SP0 includes battery 331, the winding of magnet SP0, the innor armature and make contact of starting magnet ST and ground. The operated circuit for the magnet SP1 will include battery B1, brush BJ2, conductor II, stepping magnet SP1, brush BK1), conductor 3 I, the outer armature and make contact of starting magnet ST and ground. The

- stepping magnet SP0 will step the brushes BJ1 to BJs of selector CS to their next or second contacts in a counter-clockwise direction. Also the stepping magnet SP1 will step the brushes 'BKO to BKs'of selector SL1 to their first contacts as before. The stepping magnet SP1 will then become re-operated, as already explained hereinabove. But as the brush BJ1 leaves its 1 of times.

first contact it causes the lamp LB to become extinguished. But .upon closure of its 1 second" contact, brush BJ1 causes the lamp LBzto become illuminated to indicate to the operator that the circuits connected to. the second lorush -BJ2 of the selector SL1which corresponds to lamp LB2lS being driven over the contacts connected to lines Kai-to K20 'for the testing .or measurementof the condition of these lines. As

the brush BKz contacts these various lines, any

grounded condition encountered by the brush BKz will'cause the impulse counter to operate and register that condition in integrated form as already explained. It is to be noted, ofcourse, that. the starting magnetST will become released each time that the brushes BK1 to BK5 have left their starting positions.- Moreover, as soon as the starting magnet ST becomes released, the-stepping magnet SP of the master or control selector CS will also become released.

The selector SL1 will, therefore, be successively operated to allow its brushes BK0 to BKs to sweep overtheir arcs a predetermined number The apparatus is shown set up so that the brushes BK0 to BKE: will sweep over their arcs five times in succession. Each sweep will be utilized to efiectively contact only the lines, such as K1 to K111 associated with but one of these arcs. It will be noted also that the five successive operations of selector SL1 accompany five successive steps of the master selector CS. In setting up the apparatus the relays SP0 and SP1 to SP should be so adjusted that the latter relays are somewhat slower to operate than relay SP0 to insure the stepping of selector CS before the other selectors SL1 to SL0 are stepped. Moreover, it is also necessary to have the testing brushes BK1 to BKa of the non-bridging type to provide a momentary open-circuit condition to release the impulse counter IC when stepping from one busy terminal to another.

Upon reaching the last (or starting) contact of the selector SL1 after its fifth cycle of operation, the starting magnet ST will become reoperated over the circuit including the winding of magnet ST, conductor 4|, brush BK5, contact '25 and brush BJ3 of selector CS, the impulse counter 10, resistor R34, battery B3 and ground. As the starting magnet ST becomes re-energized, the stepping magnet SP0 of selector CS will also become re-operated. It may be assumed that the brush 3J3 of selector CS has reached the contact 5| of the third arc of the selector and that brushes BJ1 and BJz have also reached corresponding positions. Upon the closure of contact 5! the stepping magnet SP5 of selector SL5 will become operated, the operating circuit including battery B1, brush BJ2, conductor l5, stepping magnet SP5 and its armature and back contact, brush BL0, conductor 45,the outer armature and make contact of starting magnet ST and ground.

The brushes BL0 to BL5 of selector SL5 will now be rotated in a counter-clockwise direction, as already described with regard to selector SL1. As the brush BL1 progressively contacts the circuits L1 to L10, the impulse counter IS-which is connected through brush BJ3, contact 5| and conductor 56 to brush BL1will allow the impulse counter IC to integrate into the previous record the number of grounded circuits encountered by the brush BL1. Thereafter the stepping magnet ST will be r'eoperated a number i of additional times to re-operate the stepping magnet SP0 of the master selector CS a corresponding number of times so as to step the brushes BJ1 to BJs in a counter-clockwise :direc-I' tion.. Each operation of the stepping magnet SP0 will be accompanied by the re-operation of the stepping magnet SP5 and the .rota-tionbf the brushes BL0 to BLs over their corresponding arcs. Likewise selector SL0 will become. operated thereafter a number of times to measure the number of grounded circuits M1 to M111 encountered by brush BM1 and by the other brushes BMz to BM5 of. the selector SL0. This need not be further described as it is in all respects sim-J ilar to the description already given.

When the brushes BM0 to BMs reachtheir last or starting contact in the last cycle of their operations, the .brush BJ1 of selectorCS will contact terminal 99, the other brushes BJz and BJgof course, being in corresponding positions. The

relay RL will then be operated overa circuit whichincludes battery B3, resistor '34, counter IC, brush BJ3 and contact 89 of selector CSI, conductor 90, brush BM5 of selector SL0, the winding of relay RL and ground. Thereupon stepping magnet SP0 will become operated over a circuit which includes battery B1, the winding of magnet SP0, the armature and make contact of relay-RL and ground. This will step selector CS to the position where brush BJ1 closes contact H] l When this happens, relay RL will be released.

. The stepping magnet SP0 will be re-operated to step brush BJ1 to-contact m2, the interconnected circuit including battery B1, magnet SP0, conductor I00, contact I0l, brush BJ1 and ground; As brush BJ1 reaches contact I02, the-magnet SP0 will be reoperated over a similar circuit to'return the brushes BJ1 to BJ; to their initial or-starting positions, as represented in the drawing.

The operator will read his impulsecounter IC and promptly determine how many of the nu'mer-. ous lines or circuits, such as K1, are ingrounded or busy condition. The operation is automatic and the record is accurate; The time required for this operation is quite small. The operator may press his key K0 at other times of the day to obtain similar'records of the circuit condition at those times. If he so desires, he may connect his key K0 to a clock-controlled circuit of well known type to obtain records of traflic conditions at regular or predetermined intervals during the day.

The operator is able to determine upon inspection of the lamps LS1 to LS0 which particular selector is in operation. At the same time the lamps LB1 to L will'indicate to the operator which of the brushes of the operating selector is contacting the lines that are associated with it to determine their electrical condition.

Although the apparatus disclosed hereinabove is intended to operate rapidly to determine the number of circuits or lines that are grounded or busy, the operating time factor may be changed as may be desired. Rotary selectors of the t pe disclosed may be slowed down substantially by adjustments of their operating mechanism. Where readings of meter IC are required after any one selector, such as SL1, has operated, the apparatus may be slowed down sufficiently so that the operator may observe from lamp LS1 (as well as lamps LB1LB5) when selector SL1 has ended its cycle and then record the number of busy or grounded circuits or lines as indicated by meter 10. This is a feature of 1 the apparatus in'that it permits the operator todetermine the number of busy lines connected to any one selector,'or to any brushof any selector. The lamp LB1, when illuminated with lamp LS1, provides indicating means to apprise the operator when brush BK]. has started and endedits portion of the cycle of selector SL1.

a telephone otfice it maybe desired to connect all of the lines or-circuits of one type to one of the 'selectorswand other lines-or circuits of a different type to another selector, and so on. The apparatus of this invention permits the operator, aided by lamps LB1LB5 and lamps LSi-LSn, to *determinehow many of the lines or circuits of each type are busy or grounded and to do 'so promptly. a.

Although this invention has been described in regard to the determination of the number or lines or circuits, such as K1,-Kz, etc.,-tha't are grounded, the apparatus may also be employed for. measuring any other electrical condition of' the lines or circuits. vFor example, the apparatusmay be employed todetermine the number of circuits which are impressed with voltages ofwa predetermined 'or excessive value, or to determine how many have a capacitancewhich'difiers from a predetermined magnitude, or to determine the number having any other resistive or reactive property.

Although this invention has been described as employing rotary selectors which step witheach operation of their stepping magnets, it will be understood that this invention may also employ selectors of the rotary or other types which step with each release of their stepping magnets as will be well understood in the art. 7

While this invention has been shown and dc.- scribed in certain particular arrangements merely for the purpose of illustration, it will be understood that the vgeneral principles-of this invention may be applied to other-and widely varied organizations without departing from the spirit .of the invention and the scope of the appended claims... What is claimed is: 1 In a measuring system for measuring the number of lines which exhibit a predetermined electrical conditiomthe combination of a master rotary selector, a plurality -of auxiliary rotary selectors 'each having a plurality of contacts. to each of which one of the lines is connected, means to operate said master selector istep-bystep in regular order, means responsive 'to'the step-by-step operation of the master selector "to separately operate said auxiliary selectors in progression so that the lines connected to said auxiliary selectors may becontacted one'at a time, an impulse counter, and means for directly connecting said counter through the master 'selector to the auxiliary. selectors, said counter heing operated whenever said predetermined electrical condition is, encountered on any line to which it is connected, thereby to 'irrclic'atejhow many of said lines exhibit said predetermined electrical condition.

2. A trarfic counter for a plurality of lines which may carry currents, comprising a master rotary selector, a plurality of auxiliary rotary selectors each of which includes a plurality of brushes mounted on a common shaft and a co'rresponding number of arts over which said brushes may rotate, the arcsof each auxiliary selector having a plurality of contacts .to which a group of said lines are connected, means to operate the master selector istep-byestep, means responsive tothe step-by-sterioperation.of the master selector to progressively, operate the various auxiliary selectors, said means including means to operate each auxiliary selector axpre determined number of times which corresponds to the number of arcs in said selector, a counter,

and means to directly connect said counter to the various arcs of the auxiliary selectors one at a time so that the counter may indicate the number of lines which exhibit a predetermined electrical condition.

3. In a. counting apparatus for counting the number of lines which exhibit a predetermined electrical condition, comprising a master selector of the rotary type, a plurality of auxiliary selectors of the rotary type, each auxiliary selector having a plurality .of brushes rotatable about is. common shaft, each brush being movable .over-an arc, each are having a plurality of contacts to which a difierent group of said lines are connected, means to operate the master selector :step-by-step, means responsive to. the step-by-step operation of the master selector to separately operate the auxiliary selectors in progression, said means including means to suecessively yoperate each auxiliaryselector a predetermined number -of times which correspond to the number of arcs i-n said selector before the next succeeding selector is operated, a counter, and means to directly'connect said counter progressively to the various arcs of each selector to indicate and record the number of lines'exhibiting the predetermined electrical condition.

4. Trafiic counting apparatus for a plurality of lines. which may carry current and become grounded when they do carry current, comprising :a master rotary selector, means for operating said master rotary selector step-by-step a plurality of auxiliary rotary selectors each having "a plurality of brushes rotatable in unison about 'a common shaft, each brush being movable over 'an/arc which :has a plurality -of contacts towhich a number of said lines are connected, controlled by :said master rotary selector for separately operating said auxiliary era'ted, afcounter, and means to directly connect each "counter to the various brushes of each auxiliary selector in a predetermined order whereby the counter will determine integrally the number dfllines which are grounded.

5. Trafl'ic measuring and indicating apparatus for a'plurality of lines which may at times exhibit a predetermined electrical condition, comprising a plurality of rotary selectors each including a plurality of brushes mounted on a-commen shaft so that they may rotate in unison, each brush beingmovable about an are having a plurality of contacts to each of which one of said :lines connected, means to operate said selectors successively, said means including meansfor successively rotating the brushes of each operated selector over their :arcs a predetermined number of times, .said brushes being rota-ted successively :over said :arcs a number of times which correspond to the number of arcs :in said selector, counting apparatus, ,means for separately connecting said counting apparatus to each or the various brushes of each selector, :for indicating which ofthe selectors is being-operated, andrurther means for indicating which brush aof anyone selector is connected to said-counting apparatus:

. CARSON.

1 imvrno PAYNE. 

